﻿<p>Chimneys are typically vertical, or as near as vertical, parts of the construction of a building and part of the building fabric. Often constructed by pre-cast or insitu concrete, today seldom by bricks.</p>
<blockquote class="extDef">NOTE&nbsp; Definition according to ISO 6707-1: 
construction containing one or more flues.<br> 
Flue: Duct designed to convey the products of combustion to the open air.<br> 
Chimney stack: Part of the chimney that projects above a roof.</blockquote>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC4.
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